This year is expected to be the strongest season for hurricanes since 2012, according to a forecast released Thursday.

In its annual hurricane outlook for the Atlantic, the National Oceanic and Atmospheric Administration said it has ratcheted up the number of storms it expects to see this year from a previous estimate, though it notes this year will not be "extremely active."

Forecasters now expect a 70 percent chance of 12 to 17 named storms this year. Of those, five to eight are expected to become hurricanes, including two to four major hurricanes, the agency said in a report.

"We've raised the numbers because some conditions now in place are indicative of a more active hurricane season," said Gerry Bell, lead seasonal hurricane forecaster at NOAA's Climate Prediction Center, in the report.

Bell said a number of forces are influencing the raised expectations, such as El Nino ending and weaker trade winds, among others. He added that some conditions such as ocean temperature patterns will likely keep the season from becoming extremely active.

Bell also said that if La Nina — the counterpart to El Nino — develops this year, it probably will not affect the season much.

Early in the season, there was a wave of tropical activity, with Bonnie striking South Carolina, Colin in western Florida, Danielle in eastern Mexico and Earl hitting Belize and Mexico.